Initial revision

progs/samples/loadppm.c

@@ -0,0 +1,72 @@
+
+typedef struct {
+    int sizeX, sizeY;
+    GLubyte *data;
+} PPMImage;
+
+static PPMImage *LoadPPM(const char *filename)
+{
+    char buff[16];
+    PPMImage *result;
+    FILE *fp;
+    int maxval;
+
+    fp = fopen(filename, "rb");
+    if (!fp)
+    {
+	fprintf(stderr, "Unable to open file `%s'\n", filename);
+	exit(1);
+    }
+
+    if (!fgets(buff, sizeof(buff), fp))
+    {
+	perror(filename);
+	exit(1);
+    }
+
+    if (buff[0] != 'P' || buff[1] != '6')
+    {
+	fprintf(stderr, "Invalid image format (must be `P6')\n");
+	exit(1);
+    }
+
+    result = malloc(sizeof(PPMImage));
+    if (!result)
+    {
+	fprintf(stderr, "Unable to allocate memory\n");
+	exit(1);
+    }
+
+    if (fscanf(fp, "%d %d", &result->sizeX, &result->sizeY) != 2)
+    {
+	fprintf(stderr, "Error loading image `%s'\n", filename);
+	exit(1);
+    }
+
+    if (fscanf(fp, "%d", &maxval) != 1)
+    {
+	fprintf(stderr, "Error loading image `%s'\n", filename);
+	exit(1);
+    }
+
+    while (fgetc(fp) != '\n')
+	;
+
+    result->data = malloc(3 * result->sizeX * result->sizeY);
+    if (!result)
+    {
+	fprintf(stderr, "Unable to allocate memory\n");
+	exit(1);
+    }
+
+    if (fread(result->data, 3 * result->sizeX, result->sizeY, fp) != result->sizeY)
+    {
+	fprintf(stderr, "Error loading image `%s'\n", filename);
+	exit(1);
+    }
+
+    fclose(fp);
+
+    return result;
+}
+